The present invention relates to modular link conveyor systems, and more particularly to a conveyor system including a side flexing belt comprised of links with one or more roller supports.
The use of side flexing modular link conveyors in the food processing industry enjoys increasing popularity. Particularly for conveying food articles or products, especially in packages or in semi-packaged form, the modular link conveyor represents the overwhelming choice of food processors. In the recent past, there have been significant advances in the development of such conveyors so as to provide more efficient handling of an even larger variety of food articles, packages and containers, as well as other types of articles and products.
One of the most popular types of modular link conveyor systems on the market today, if not the most popular, is The Designer System, manufactured and sold by the assignee of the present invention, and illustrated and claimed in prior U.S. Pat. No. 4,953,693, Sep. 4, 1990 and U.S. Pat. No. 5,031,757, issued Jul. 16, 1991. Since the time of these early patents in the art, the significant advances have been fast in coming to provide an even more efficient operation and better handling and transporting of articles and products.
One such advance is the provision of side mounted rollers for smoothly guiding the side flexing conveyor belt around curves, such as illustrated and claimed in co-pending application Ser. No. 09/131,587, filed Aug. 10, 1998 entitled xe2x80x9cExternal Guide Assembly for Reducing Conveyor Belt Dragxe2x80x9d and assigned to the assignee of the present invention. Specifically, stationary mounted spindles with idler rollers adjacent the curves have proven to be highly effective in reducing the side drag along the path. This advantageously serves to somewhat reduce the driving power requirements, as well as the modular link wear attributed to the lateral forces. Others have proposed providing openly mounted rollers carried on the modular links themselves, and acting against the inside of an upstanding rail in an attempt to accomplish the same result, as illustrated in U.S. Pat. No. 5,775,480, issued Jul. 7, 1998.
There also exists in the prior art relating to chain conveyors, the provision for rollers for supporting the chain, as well as for lateral guiding action. Each chain link mounts the rollers in the open, and upper and lower guide tracks are provided, as set forth for example in a U.S. Patent No. to Clopton 5,076,422, issued Dec. 31, 1991. A similar, but much earlier arrangement providing both support and lateral guiding of a conveyor chain is shown in the Gaiotto et al. U.S. Pat. No. 3,575,282 issued Apr. 20, 1971.
Thus, while support/guide rollers mounted on chain conveyors have been successfully tried for almost two decades, a need is identified for providing a successful arrangement for support rollers mounted on the conveyor belt in a modular link conveyor system. So far, such a solution has escaped those working in the conveyor technology. If such an advance in modular conveyors is to take place, it must compliment the effective guiding action achieved by the side rollers mounted along the guide rails, and thereby enhance the overall operation of the conveyor system.
In accordance with the purposes of the present invention as described herein, an improved modular link conveyor system and a side flexing belt for transporting articles along a longitudinal path are provided. The belt may comprise a plurality of modular link sections that extend in both the longitudinal and transverse directions, with each unique link section including interengaging apex and leg portions. A transverse connector extends through matching apertures to provide the side flexing action. An extended support surface for the transported articles is provided on the upper side of the links. At least one, but preferably multiple, spaced support rollers are provided in an enclosure on the underside of at least one portion of a corresponding link section. Preferably, the enclosure is formed in at least one apex of the modular link section, but may also be formed in each apex present during molding to enhance the design flexibility. The roller may be aligned and specially adapted for rolling on a longitudinally extending support surface, such as a rail. The rail gives a very efficient support arrangement for the weight of the conveyor belt and transported articles. As a result, smooth, substantially friction free support of the belt is obtained, even when the number and weight of the articles being handled is significantly increased. This enhancement also advantageously serves to both minimize the power driving requirements and significantly reduce the wear on the link sections.
Because each roller is mounted in an enclosure, debris build up around the roller, such as inadvertent spillage from transported food products, is minimized. The enclosure in accordance with the preferred embodiment extends in close proximity to the two sides of the roller and along at least the upper roller face. For the greatest effectiveness, the enclosure forms a curved cap having a lip and depending skirt covering substantially 180xc2x0 of the rolling face of the roller.
In the case of a support rail, a support or wear strip fabricated of plastic is provided to create a smooth track surface for the support roller to roll on. Preferably, the modular link sections of the conveyor belt are molded of low cost, polypropylene plastic, whereas the roller and this support strip are formed of high strength, wear resistant plastic, such as acetyl or Nylon. An alternative to a support rail or the like is to merely provide a flat, plate-like support structure for engaging the roller(s).
At least one support roller may also be mounted in a modular side link section for assisting in guiding the conveyor belt. A depending arm and transverse tab are provided on each of these sections to engage the side and lower faces of the rail or other support structure so as to double for providing lateral guiding action of the belt. Preferably, at least two side by side, integral modular link sections form a composite link, which in turn establishes an extended upper support surface for the articles being transported. As a result, smaller items, such as bottle caps, are particularly adapted for transporting on the conveyor system. The extra smooth operation generated by the roller support feature, that thus eliminates any tendency for the support surface to vibrate and cause such small articles to move on the surface, adds to the desirability of the conveyor system of the present invention.
The transverse connector to form the belt is preferably a plastic or metal rod that extends through a slot or oversized opening in the apex portion and a hole in the leg portion. As should be appreciated, this arrangement allows for the desirable smooth, side flexing action. Lock elements carried by the side link sections may be used to couple the rod to the belt.